1. Field of the Invention
The present invention relates to a cruise control device for vehicles, and more particularly to a cruise control device for vehicles comprising a pedal shaft formed on the link part of an vehicle's accelerator, a gear rotatably fitted on the pedal shaft, and an adjusting unit releasably engaged with the gear for adjusting the position of an accelerator pedal, thereby quickly and safely maintaining the constant speed of the vehicle mechanically.
2. Description of the Related Art
The speed of a vehicle, stemming from the generation of power by means of the combustion stroke of an engine of the vehicle, is generally controlled by means of a brake pedal, a clutch pedal, and an accelerator pedal. The opening angle of a throttle valve, through which mixed gas is supplied to the combustion chamber of the engine, is changed depending on the degree which the accelerator is depressed.
When the accelerator pedal is deeply depressed, the combustion rate of the fuel is increased, thus the vehicle accelerates. On the other hand, when the accelerator pedal is depressed slightly, the combustion rate of fuel is decreased, thus the vehicle decelerates. Consequently, a driver controls the speed of the vehicle via the accelerator pedal.
Although the speed of the vehicle is properly controlled by means of the accelerator pedal on the basis of road conditions, it may be preferable to maintain a constant speed of the vehicle for a desired period of time. In this case, the accelerator pedal must be depressed at a constant level.
In the case where a vehicle is driven at a constant speed, the consumption rate of fuel is reduced, and vehicle components are not overstrained. However, it is difficult, even for a skilled driver, to maintain a constant speed under various conditions.
A cruise control device for vehicles, which is capable of maintaining a constant speed has been developed in order to solve the above-mentioned problems. The cruise control device, which comprises complex mechanical units and complex electronic units, controls the throttle valve to maintain the speed of the vehicle at a predetermined speed.
However, the cruise control device, which controls the throttle valve to maintain the constant speed of the vehicle, has an asynchronous feedback mechanism such that the opening angle of the throttle valve is controlled by means of a driving part, i.e., an actuator, on the basis of the response of a sensor. Consequently, the response speed is very low.
Furthermore, the constant speed of the vehicle is not quickly released in case of an emergency while the vehicle is driven, which may lead to injury of the driver. Also, the durability of the electronic units deteriorates.